A friend of mine is looking at buying a boat (and so am I, but I think I've found mine).<br /><br />It is a tunnel boat, Bayhawk, with a 90hp Johnson on it. I has a 4 blade prop (not sure of the pitch), and a 'doelfin'. <br /><br />While we were testing it, I noticed that while at cruising speed, if you try to go faster and top the engine out...it would accelerate and hold the speed for a few seconds, and then it would act like the prop had no load on it and it was free-spinning. I have never experienced cavitation, but I assume that is what this was, am I correct?<br /><br />Ok, no big deal...cavitation, There is only so much that can be causing it. So, we experiment a little more, and it continues to do it, so we take the boat back to the ramp where the seller is waiting.<br /><br />As we pull into the sellers driveway, I notice that the seller never removed the 'muffs' from when he ran the boat on the water hose earlier. Therefore, there was an obvious water distraction mounted to a major hydrodynamic area of the engine during the whole 'test ride'. <br /><br />Could this have caused the boat to act funny due to the water flow being irritated when it went past the 'muffs'? This is inline with part of the prop, and I would THINK it could cause 'cavitation', or something similar.<br /><br />The water pressure on the boat was good, and it didn't overheat. The muffs slid back and allowed plenty of water into the inlets, thankfully.<br /><br />I'm just curious if this could be his 'cavitation' problem, or if he needs to worry elsewhere. We would just go 'test' it again, without the muffs, but it is a 2hr drive. The seller said he never had any problems with cavitation, and that the muffs had to be the culprit.<br /><br />Any feedback?<br /><br />Thanks!<br />Shawn
<br /><br />Thanks guys<br /><br />Shawn